Disconnect arrangement for multi-unit printing press

ABSTRACT

A disconnect arrangement for individual units of a multi-unit press in which the throw-off eccentrics and the stock-thickness adjustment eccentrics for the blanket cylinder are selectively interconnected for simultaneous operation to impart additional throw to the blanket cylinder to shift the blanket cylinder out of mesh with the driving gear. A timing gear train and a single position clutch assure re-engagement of the blanket cylinder in the proper timed relationship. Means are disclosed for returning the stock thickness mechanism to its original setting upon reengagement of the blanket cylinder.

United States Patent Kist et a1. 1 1 Apr. 2, 1974 [54] DISCONNECT ARRANGEMENT FOR 2,773,445 12/1956 Wood 101/218 MULTLUNIT PRINTING PRESS 2,866,408 12/1958 Stevenson t 101/139 X 2,944,482 7/1960 Allen 101/177 [75] Inventors: Karl E. Kist, Strongsville; Donald F. 3 030,3 4 4 1962 Lindcmann,,,, 101/218 Elmore, Dayton, both of Ohio 3,112,695 12/1963 Seel 101/177 X 3,221,651 12/1965 Ta 1iasacchi.. 101/183 [73] AS81811: l corpm'amn 3,280,737 10/1966 Hu ck 101/181 Cleveland, Ohm 3,516,355 6/1970 0111111713.... 101/183 J Mascord .1 12] 1 Appl' 3745: Primary Examiner-.l. Rccd Fisher Related U.S. Application Data [63] Continuation of Scr. No. 85,131, Oct. 29, 1970, [571 ABSTRACT abandoned A disconnect arrangement for individual units of a multi-unit press in which the throw-off eccentrics and 2% 8 1 3 3: the stock-thickness adjustment eccentrics for the blan i b 136 g ket cylinder are selectively interconnected for simulta- 1 le 0 1 neous operation to impart additional throw to the l blanket cylinder to shift the blanket cylinder out of mesh with the driving gear. A timing gear train and a [56] References C'ted single position clutch assure're-engagement of the UNITED STATES PATENTS blanket cylinder in the proper timed relationship. 1,818,751 8/1931 Quick et al.. 101/247 Means are disclosed for returning the stock thickness 2,003,798 6/1935 Barber 10 177 mechanism to its original setting upon re-engagement 2,026,434 12/1935 Quick 61 al.. 101/247 f the blanket cylinder. 2,258,653 10/1941 Klingelfuss lOl/247 2,568,761 9/1951 Peyrebrune 101/218 23 Claims, 8 Drawing Figures mgmfnm 21914 3.800.698

sum 1 Hf, 6

E lllllll|||||||||||||||||||l|||||||||||| INVENTORS KARL 5 Klsr DONALD E ELMO/4 6 ATTORNEYS PATENTEDAPR 21914 3.800.698

SHEET 2 [If 6 KAPL E K/ST DOA 4L0 E ELMORE A 770/?NEYS PAIENIEBAPR 2:974 $800,698

- sum u 0? 6 FIGB //V VENTORS KARL E. K /S7 00M4Lp E ELMOKE A TTOR/VEYS PATENTEDAPR 2 m4 SHEET 5 (IF 6 0v 0 MTMJM Mu Mm N 50% L LA M w This is a continuation of application Ser. No. 85,131, filed Oct. 29, 1970, now abandoned.

This invention relates to printing presses and, particularly to a disconnect arrangement for allowing the image carrying cylinder means of the individual units of a multi-unit printing press, such as the blanket and plate cylinders of a sheet fed multi-color offset lithographic press, to be rotated separately from the other units for make-ready or clean-up purposes even though the cylinder means of the various units are intergeared during normal printing operations.

Although the invention is particularly useful in three cylinder offset sheet fed presses, it will be appreciated that the concepts may be used in other types of presses.

When a multi-unit printing press is being readied for a printing run, and sometimes during a printing run, it is necessary or desirable to perform certain make-ready or clean-up operations on the individualunits of the press. While readying a printing press for printing operations or when cleaning up the press, it is highly desirable that different pressmen be able to drive at least the image carrying cylinder means of the different printing units independently of each other so that more than one man can work on the various printing units and jog the image carrying cylinder means of the unit as desired without endangering the men working .on the other printing units. However, it is apparent that if all the image carrying cylinder means of the different printing units are geared together during make-ready or clean up, as they are during normal printing operation, only one pressman can safely work on the press for those operations which require a cylinder of the individual units to be rotated for the make-ready or clean-up operations.

To facilitate make-ready and clean-up, it has been heretofore suggested, in sheet fed printing presses, to disconnect the entire individual printing units from each other and to provide auxiliary motors whereby the entire disconnected units can be individually rotated. In this way, different pressmen can work on different units with each individual unit being rotatable separate from the other units. In such systems the impression cylinder of the unit has normally been driven with the unit after the disconnect and the transfer cylinders between the units have commonly been driven with one of the adjacent units although in one machine it has been locked in position to maintain timing.

The disconnection means for disconnecting a printing unit has generally incorporated a one-toothed clutch or a pin in the main drive to provide for the reconnection of the units in their proper angular relationship. These pins and one-toothed clutches have carried driving forces for the units during normal printing. It is preferable that drives for printing units be through gear teeth during the normal printing operation.

It is an object of the present invention to provide a new and improved multi-unit printing press in which the individual units which are interconnected during running may be operated independently of each other for make-ready, etc-., the press being so constructed and arranged that the printing cylinder units to be disconnectable may be individually shifted to throw the drive gear on the printing cylinder out of mesh with its driving gear to disconnect the printing cylinder from the main drive of the press so that the printing cylinder may be driven independently of the main drive train for make-ready purposes, the disconnect mechanism preferably including timing means for reconnecting the printing cylinder with the main drive train at the proper angular relationship to maintain the timing of the press.

It is another object of the present invention to provide a new and improved multi-unit printing press in which the printing cylinders of the units can be thrown out of meshing engagement with their drive gear so as to be disengaged from the press drive train and driven independently of the press drive and of each other for make-ready and clean-up purposes and in which the main press drive may be operated to rotate the main press drive train and the impression cylinders of the press to effect a reconnection of the disconnected printing cylinders when the printing cylinders have the proper phase relationship with the press drive.

It is a more specificobject of this invention to provide an improved disconnect arrangement for individual units of a multi-unit sheet fed press and which is operable without interfering with the sheet handling cylinders or the ability of these cylinders to handle sheets when one or more units are disconnected.

It is a further object of this invention to provide an improved disconnect arrangement which includes improved means for shifting the blanket or printing cylinder of each unit of a multi-unit press out of mesh with its associated driving gear and means for reconnecting the units in the proper timed relationship.

It is another object of the present invention to provide a new and improved throw mechanism for a printing cylinder in-which .the cylinder may be moved or thrown laterally to throw the pressure on and off without losing the meshing relationship of driving gears for the printing cylinder or of timing gears which interconnect the driving gears and may be moved an additional distance laterally to lose the meshing of the driving gears but not of the timing gears.

It is a still further object of this invention to provide a disconnect arrangement for a printing press unit which utilizes a conventional cylinder throw-off and stock-thickness adjustment mechanismto effectthe disconnect.

The invention also contemplates a multi-unit printing press in which a printing cylinder which is movable between printing and non-printing positions while its drive gear remains in mesh with a driving gear is also movable to non-printing condition in which the drive gear is out of mesh with its driving gear to thereby disconnect the printing cylinder so that it can be driven separately from the main press drive by an auxiliary motor, the printing cylinder, if the press is a lithographic press, preferably having positions on and off the plate cylinder with its drive gear out of mesh with its driving gear.

It is'another object of the invention to use a conventional stock-thickness mechanism in the disconnect sequence and provide means for returning the mechanism to its original setting upon re-engagement.

More specifically, and in accordance with the principles of this invention, the printing cylinder is so constructed and arranged that it may be thrown off and on printing pressure in a conventional manner without.

being disconnected from its drive but when it is desired lar relationship of the cylinders and not to transmit drive therebetween during printing.

More specifically, the timing gears include disconnect means in the form of a solenoid actuated pin which is operable to disconnect a timing gear' associated with the blanket cylinder from a timing gear associated with the impression cylinder. The pin can be reconnected in only one angular position of the timing gears thereby assuring that upon reconnection of the timing gears, the proper angular relationship between the plate, blanket and impression cylinders is reestablished. Safety means are provided so that when the blanket cylinder is disconnected, the auxiliary motors for the individual units cannot be started to drive the units until the solenoid actuated pin has been energized thereby disconnecting the timing gear train and precluding the transmission of drive through the timing gears.

It is conventional to support a blanket cylinder in eccentrics which are rotated to effect the shifting movement of the blanket cylinder to its on and off pressure positions. In addition, a stock-thickness mechanism is normally provided for adjusting the final position of the cylinder relative to the impre ssion cylinder to adjust for various stock thicknesses. This stock thickness mecha-, nism commonly includes second eccentrics which surround the eccentrics comprising the throw out mechanism so that rotation of the inner eccentrics throws the cylinder off and on pressure while rotation of the outer eccentrics adjusts the position of the cylinder for stock thickness. In accordance with a specific form of the preferred embodiment of this invention, the inner throw off eccentric carries a solenoid operated pin which, upon energization of the solenoid, is receivable in an opening in the outer eccentric thereby coupling the two eccentrics for unitary movement. With this arrangement, the blanket cylinder may be moved to its normal on and off pressure positions through operation of the conventional throw off mechanism which rotates the inner eccentrics. However, when it is desired to throw the blanket cylinder out of mesh with the press drive train, the solenoid is actuated to couple the inner eccentric to the outer eccentric with the two eccentrics providing the additional throw necessary to move the blanket cylinder out of mesh. An additional feature of a specific form of the invention is the provision of means associated with the stock thickness mechanism to automatically re-establish the previously set position of the stock thickness adjustment mechanism when the blanket cylinder is moved back into meshing engagement with the drive train.

Further objects and features of the present invention will be apparentto those skilled in the art to which it relates from the following detailed description of the preferred embodiment thereof made with reference to the accompanying drawings forming a part of this specification and in which:

' erence numeral 22, supplies sheets to the first FIG. 1 is a schematic side elevational view of a lithographic multi-unit sheet-fed printing press in which the invention may be employed;

FIG. 2 is a view showing various positions to which the blanket cylinder of a printing unit may be moved;

FIG. 3 is a view somewhat diagrammatic of mechanism for moving a blanket cylinder;

FIG. 4 is a view taken approximately along line 4-4 of FIG. 3;

F IG. 5 is a view showing drive gears and timing gears in one of the units;

FIG. 6 is a view taken approximately along line 6-6 of FIG. 5;

FIG. 7 is a view of a stock adjustment restorer;

FIG. 8 is a sectional view of part of the adjustment restorer mechanism;

FIG. 9 is a circuit diagram for use with the press of FIG. 1; and

FIG. 9a is a switch position diagram.

Referring now more in detail to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment only and not for the purposes of limiting same, there is illustrated in FIG. 1 a multi-color sheet-fed offset lithographic press, generally indicated by the reference numeral 10, and which comprises a plurality of units, three of the printing units, 11,12 and 13, being shown. As is well understood in the art, each of the printing units includes an impression cylinder 16, and cylinder means comprising a blanket cylinder 17 and a plate cylinder 18 which carry the image to be printed. Each unit also includes a dampening mechanism 19 and an inking mechanism 20', each of which is conventional in the art and functions in conventional manner to supply dampening fluid and ink to the plate. cylinder 18. I

A feeding mechanism, indicated generally by the refprinting unit 11 through a feed cylinder 23 and an advance cylinder 24 which transfers the sheet to the impression cylinder 16 of the first printing unit. The sheet is then carried through the printing nip of the first printing unit by the impression cylinder 16 and is transferred to a first double size transfer cylinder 25 which carries the sheet to the impression cylinder of the second printing unit 12. In this manner, the sheet passes through each of the printing units and is ultimately delivered to a de- I livery mechanism, shown schematically and indicated by the reference numeral 26.

The press is driven by a main drive motor 27 shown schematically as driving the'first transfer cylinder. The cylinders of the press are intergeared in aconventional manner with the transfer cylinders having gears which mesh with gears on the adjacent impression cylinders and the impression cylinder gears drive gears on the respective blanket cylinders which, in turn, drive gears on the associated plate cylinders. The ink rolls and dampener rolls, if driven by the press drive, may be driven from the gears on the plate cylinders.

Referring again to FIG. 1, the drive arrangement between the impression, blanket and plate cylinders of the units is schematically illustrated for each unit and the drive comprises a gear 30 which is secured for rotation to the impression cylinder shaft 32 and which meshes with a blanket cylinder drive gear 34 secured to the blanket cylinder shaft 36. The gear 34 meshes with a plate drive gear 38 carried on the plate cylinder shaft 39. Each of the gears 30, 34 and 38 are disposed on the inside of the frame 40 of the press.

In the printing press illustrated in FIG. 1, the blanket cylinders are each supported for movement between an on pressure position for printing in which it has a pressure relationship with the plate and with the impression cylinder of the unit, at least when stock is fed therebetween, and an off pressure non-printing position in which it is clear of the plate and impression cylinder. In the normal off pressure position, the gears 34 on the blanket cylinders remain in meshing engagement with the impression gears 30. The two primary positions to which the blanket cylinder may be shifted are illustrated in FIG. 2 with the on pressure and its axis of rotation being indicated at A, while the off pressure position and its axis of rotation being indicated at B.

Referring now to FIG. 3, the arrangement for effecting the shifting movements of a blanket cylinder of the press is schematically illustrated. As shown in that figure, the blanketcylinder shaft 36 is eccentrically and rotatably supported by an appropriate bearing 42 in a rotatable bushing 44, hereinafter referred to as an eccentric or eccentric bushing. The eccentric 44 is connected by appropriate lug means 46 to a conventional throw mechanism 48 including a rocker member 48a. By actuating the throw mechanism 48, the eccentric 44 is rotated about its axis of rotation 54 (FIG. 2) to shift the axis of rotation of the shaft 36, and hence throw the blanket cylinder 17, to throw the cylinder to its respective on and off pressure positions shown at A and B in FIG. 2. In the on pressure position, the throw of th rocker member is limited by a stop 48b.

It will be understood that the present invention is also applicable to printing presses in which double eccentrics are used to throw to the plate in one movement and to the impression in another movement, with the throw to establish plate pressure being actuated by mechanism separate from that to establish impression pressure.

In addition to the eccentric 44, a second eccentric bushing 50 rotatably supported by frame 40 is provided. The second eccentric rotatably and eccentrically supports the first eccentric and, for purposes of this disclosure, the eccentric 44 will be referred to as an inner eccentric and the eccentric 50 as the outer eccentric. The eccentric 50 is supported in the'frame 40 for rotation about an axis 51 (FIG. 2) which is offset from the axis of rotation of both the eccentric 44 and the shaft 36. A lug 52 fixed to the eccentric 50 is connected through an appropriate linkage 53 to a stock-thickness adjusting mechanism, indicated generally by the reference numeral 56. The mechanism 56 may comprise a rotatable gear 57 in meshing engagement with a worm gear 58 on a rotatable shaft 59. A manually operable hand wheel 60 is connected to the shaft 59. The shaft 59 is connected to a clutch 61 which is driven by a motor 62 through a worm and worm wheel drive, With this arrangement, the eccentric 50 may be rotated to shift the position of the blanket cylinder either by manual rotation of the hand wheel 60 or through operation of the motor 62 and clutch 61.

In the illustrated embodiment of this invention, means are provided to interconnect the inner eccentric 44 with the outer eccentric 50 to impart additional throw to the blanket cylinder 17 to move the blanket cylinder gear 34 out of meshing engagement with the 6 impression cylinder gear 30. More specifically, refer.- ring to FIG. 3, this is accomplished by an arrangement which includes a bracket 64 carried by the inner eccentric 44 and extending over the outer eccentric 50. The bracket 64 carries a solenoid operated pin 66 which, upon energization of a solenoid 70, can be moved into a pin-receiving opening 67 in the outer eccentric thereby to connect the inner and outer eccentrics for unitary movement. With this arrangement, the blanket cylinder is moved to an off pressure position by the conventional throw-off mechanism and, through energization of stock-thickness motor 62 and the solenoid 70, the two eccentrics may be interconnected by the pin 66 and moved to rotate both eccentrics 44, 50 simultaneously to move the blanket cylinder 17 laterally.

supports the solenoid 70 having a movable armature 72' which is connected by a pivotally supported crank or lever 74 to the solenoid operated pin 66. It will be appreciated that upon energization of the solenoid 70, the

armature 72 is retracted thereby pivoting the lever 74 and displacing the pin 66 axially into the opening 67 in the outer eccentric.

To limit the movement of the inner eccentric during the normal throw-off operation, there is provided a stop dog 75 which is carried by the pin 66 and which is adapted to engage an adjustable fixed stop 76 on the frame of the press. The stop dog 75 is connected for movement with the pin 66 so that when the inner eccentric is coupled to the outer eccentric by actuation of the pin 66, the stop member 75 is moved to the dotted line position 75'. In this position, the stop dog clears the fixed stop 76 and pennits the inner eccentric to rotate beyond the stop with the outer eccentric to provide the additional throw necessary to move the blanket cylinder out of mesh with the drive gear on the impression cylinder.

In the illustrated embodiment, when the blanket cylinder gear is out of mesh with the drive gear on the impression cylinder, the blanket cylinder may bein an OFF-PLATE or an ON-PLATE position. In the OFF- PLATE position, the blanket is separated from the plate while in the ON-PLATE position, the eccentric is thrown an additional distance and the blanket is moved into engagement with the plate with the drive gears between the blanket and impression cylinders remaining out of mesh.

To assure the-proper timed relationship between the cylinders upon re-engagementof the blanket cylinder drive gear with the impression cylinder drive gear, a timing mechanism'is provided. This mechanism is illustrated in FIGS. 5 and 6 and comprises timing gear means with a clutch which may be engaged when the clutch members are in only one relative angular position thereby assuring coupling of the timing gear means in the proper timed relationship. More specifically, the blanket cylinder shaft 36 extends through the frame 40 and has secured to the outer end thereof a timing gear 80. The gear 80 meshes with a gear 82 which is supported on a stub shaft 84 rotatably supported in the frame 40. The gear 82 meshes with timing gear 86 rotatably supported on a shaft 87 carried by frame 40.

The gears 86, 80 remain in mesh with the idler gear 82 when the blanket cylinder is moved to disengage the gears of the blanket and impression cylinder. FIG. 2 illustrates the center of the blanket cylinder shaft for the various positions of the blanket cylinder. Position A in FIG. 2 indicates the on. pressure position, the position B indicates the shaft center line position for the normal off pressure, position C indicates the position for the OFF-PLATE but out of mesh position of the cylinder and position D indicates the position for ON- PLATE and out of mesh. From FIG. 2 it canbe seen that the eccentrics shift the axis of the driving gear 34 and of the timing gear 80 on the shaft of the blanket cylinder 17 along a line which is almost parallel to the line of action between the teeth of the timing gear 80 and of the gear 82 shown in FIG. 5. This line has a major component ofmovement along a line joining the axes of the gears 30 and 34 for driving the impression and blanket cylinders, respectively so that these gears will move out of mesh even though the movement is not enough to disengage the teeth of the timing gears 80 and 82.

Rotatably supported on the same shaft 87 as the gear 86 is a second timing gear 88 which is in meshing engagement with a cooperating gear 90 secured to an end of the impression cylinder shaft 32 for rotation with the impression cylinder and its drive gear 30.

Referring to FIG. 6, the shaft 87 also rotatably carries on its outer extremity, throw-out collar 92 which includes an axially projecting clutch pin 94. The pin 94 normally extends through an axially extending opening 96 in the gear 86 into an opening 97 in the gear 88. The pin 94 is adapted to be shifted by the collar 92 to a position where it is clear of opening 97 in the gear 88 to disconnectthe timing gears and allow independent rotation of the blanket and impression cylinders. The throw-out collar 92 and its associated pin 94 are shiftable axially along the shaft 87 by a throw-out yoke 98 which is connected by a pivoted lever portion 99 to a solenoid actuator 100. A spring 101 connected to lever 99 normally biases collar 92 to a position where pin 94 extends into opening 97. It will be appreciated that as the solenoid 1I )0 is energized, the yoke 98 will shift the collar 92 axially on the shaft 87 to withdraw the pin 94 from the opening 97 in the gear 88, thereby disconnecting the two gears 86, 88 forindependent rotation. In this way, the timing gears 80, 82, 86, 88 and 90 may be selectively coupled for unitary rotation but, when desired, the train may be interrupted so that the gears 80, 82 and 86 rotate independently of the gears 88 and 90.

In the illustrated embodiment, when the blanket cylinder gear 34 is in meshing engagement with gear 30, the pin 94 will couple the two gears 86, 88 together for unitary rotation. However, it is to be noted that the timing gears are not designed to transmit the drive from the impression cylinder to the blanket cylinder during printing since this drive function is performed by the gears 30, 34 and that during normal operation when the cylinder gears 30, 34 are in mesh, the pin 96 may be disengaged if desired. The only function of the timing gear train is to enable the establishment of the proper timed angular relationship between the cylinders after the blanket cylinder has been thrown ofi and out of mesh with gear 30. The timing gears enable the proper angular relationship to be re-established and maintained as the gears are brought back into mesh.'This is accomplished in the following manner. On disconnection of the blanket cylinder from the main press drive,

8 the solenoid 100 is actuated to withdraw pin 94 from the aperture 97 thereby disconnecting the timing gear 86 from the timing gear 88. Thereafter, the blanket cylinder may be rotated through actuation of an auxiliary motor 102, clutch 104 and gears 82 and 80. The gear 86, which is in meshing engagement with the gear 82, will rotate as themotor 102 is operated but, because the gears 86, 88 are now disconnected, no drive will be transmitted to the impression cylinder. Moreover,

operation of the main press drive will transmit no drive to the blanket cylinder.

When it is desired to reconnect the blanket cylinder with the main press drive, the solenoid 100- is deenergized and the main press drive is operated to rotate the impression cylinders, together with their associated gears, until the opening 97 is aligned with pin 94 whereupon spring 101 displaces collar 92 to move pin 94 into the opening. Since clutch pin 94 is receivable in the opening 97 in the gear 88 in only one angular position thereof, it is apparent that, upon re-engagement, the proper timed relationship is re-established between the cylinders of the unit. The drive pin 94 will maintain the relationship by driving the blanket and plate cylinders if the press drive continues operation with the impression and blanket cylinders out of mesh. I

It is to be understood that the blanket cylinder drive gear 34 remains in mesh with its associated; plate cylin-- der gear when the blanket gear is out of mesh with the impression cylinder gear 30. Consequently, operation of motor 102 also operates the plate cylinder.

' Referring now to FIG. 9, there is illustrated a circuit for controlling the engaging and disengaging sequence for one of the units of the printing press. It will be appreciat'ed that, in a multi-unit press, a similar circuit would be employed for each individual unit to, have the disconnect feature, preferably all of the units. To facili-- tate an understanding of the circuit, the notations employed in that figure are as follows. The numbers in the right-hand column opposite each line in which a relay coil is illustrated refer to the lines in which the relays are actuated by that coil. The underlined numbers refer to a normally closed relay and the numbers without underlining indicate the relay is normally open. As an example, there is illustrated l in line 23 a relay coil CR1 10-C which, when energized, actuates normally open relays CRllO-l in line 10 and CRll0-2 in line 12 and normally closed relay CR1l0-3 in line 31. The

' remainder of the circuit will be described, to the extent necessary, with reference to the operation of the print- 1 ing press. I

Turning now to the operation of, the press, there is provided a make-ready switch which may be moved to any of these different positions, connect, OFF-PLATE and ON-PLATE. The circuit further includes an off pressure switch 122, an eccentric pin engaged switch 124, a timing pin disengaged switch 126, an off-home switch 128, an OFF-PLATE switch and an ON-PLATE switch 132. The switches 128, 130 and 132 are controlled by a bank of cams 134 connected to the stock thickness adjustment gear 57.

Assuming it is desired to disconnect one of the units in an OFF-PLATE position, switch 120 is moved to the OF F-PLATE position. However, to assure that the disengage sequence is not initiated until after the blanket cylinder has been thrown off pressure, off-pressure switch 122 is provided. This switch 122 is positioned adjacent a rocker member of the throw mechanism and is open when the blanket cylinder is in an on pressure position and closes when the eccentric 44 has been rotated to throw the blanket cylinder off pressure. Closure of switch 122 as the blanket cylinder moves to the off pressure condition readies the circuit for the disconnect sequence.

To initiate a disconnect, the switch 120 is put into an OF F -PLATE or ()N-PLATE position. When the three position switch 120 is in its OFF-PLATE position, its contacts 120A and 1208 are closed. FIG. 9a illustrates the condition of the contacts for the various conditions of switch 120 with an X mark indicating that the contacts are closed and a mark indicating that the contacts are open. With the contacts 120A closed, the relay coil CR116-C is energized to close contacts CR116-1 in line of the circuit diagram to condition a circuit for energizing the solenoid 70 for engaging the eccentric pin 66 for interconnecting the inner and outer eccentrics 44, 50. The eccentric pin solenoid is energized through the contacts CRl16-1 provided the blanket has been thrown off pressure in a conventional manner to close off pressure blanket switch 122 and energize relay coil CR1 l0-C which has normally open contacts CRllO-l in series with the eccentric pin solenoid 70 and the contacts CR116-1. The circuit for energizing the eccentric pin solenoid 70 also effects energization of the motor 62 and its clutch 61 to drive the eccentric 50 through the stock thickness adjusting mechanism by energizing a motor forward and clutch relay coil MFl20-C through the contacts CRll6-l and CR1 10-]. This starts the motor 62 running in a direction to position the opening 67 in the outer eccentric to receive the eccentric pin.

When the eccentric pin engages the outer eccentric, the switch 124 closes to energize the relay coil CR1 ll-C. This opens contacts CRlll-l to break the initial energizing circuit for the motor forward relay coil MF120-C but completes a holding circuit byclosing contacts CRl11-2 to complete a holding circuit through the contacts 1208 Of the switch 120, the switch now being in its off plate position. This continues the operation of the motor 62 to move the eccentrics to throw the blanket cylinder to an off plate condition. When the blanket cylinder is in its off plate condition, the switch 130 is closed to energize a relay coil CR114-C; This relay has normally closedv contacts CR114-3 in the circuit for energizing the motor forward coil MF120-C through the contacts 120B of the switch 120, the contacts stopping the motor when relay coil CRl14-3 is energized. If the switch 120 had been set to an on plate position, the holding circuit for continuing the operation of the motor 62 to throw the eccentrics would have been completed through the contacts CR11l-3 closed by the relay coil CR111C when the eccentric pin is engaged and contacts 120C of the switch 120. In this case, the motor 62 operates until the switch 132 is closed to energize the relay coil CRllS-C to open normally closed contacts CR1 15-2 in series with the motor forward coil MF120-C. The energization of the relay coil CR1 14-C by the closing of the switch 130 as the eccentric moves to its OFF- PLATE position also closes contacts CR114-2 to energize the timing solenoid 100. The contacts CRl14-2 are in series with contacts CR116-3 and contacts CR110-2 which are now closed because of the energization of the relay coil CR 116-C by the selector switch 120 and the energization of relay coil CR1 10-C by the ofi pressure switch 122. With the timing pin solenoid energized, the timing pin is withdrawn from the timing gear 88 to allow independent rotation of the blanket cylinder and the impression cylinder. Withdrawal of the timing pin solenoid closes switch 126 to energize relay coil CR112-C to open its contacts CR112-2 in the circuit for initially energizing the eccentric pin solenoid. The solenoid, however, is maintained energized through a holding circuit made by contacts CRll3-1 of a relay coil CRll3-3 which is energized by movement from the off-home position of the inner eccentric. Thus, the eccentric pin will be withdrawn only when the relay coil CRl13-C is de-energized when the inner eccentric is returned to home position.

If the eccentric pin is not received in the outer eccentric when the motor 62 is operated to effect such engagement and the opening moves by the pin in the outer eccentric for receiving the timing pin, the motor 62 will be reversed and another pass at engagement made. When the opening in the outer eccentric moves past the pin, the off-home switch 128 is closed and indicates that the eccentric pin should have been picked up. This switch energizes relay CRl13-C to close its contacts CR1 13-4 in the circuit for energizing a motor reverse relay coil MR12l-C. Energization of coil MR12l-C closes contacts to engage clutch 61 and operate the motor 62 in a reverse direction. This circuit for coil MRl21-C is made through contacts CRlll-S of the relay coil CRlll-C which are normally closed contacts and which are now closed because the eccentric pin switch 124 was not actuated to indicate that the eccentric pin had engaged. The motor is operated in a reverse direction until the off-home switch 128 is again opened to deenergize coil CRl13-C to open its contacts CR1 13-4 to deenergize reverse coil MR12l-C and to close its contacts CR1l3-3 to again energize forward coil MFl20-C. The coil CRll3-C drops out with a time delay to assure that the outer eccentric will be returned a sufficient distance to be able to pick up the pin 66 when themotor 62 is again operated in the next pass. If engagement had been made,

the switch would be closed, the relay coil CRlll-C energized and this circuit would not be made to reverse the motor.

It will be further noted that the motor forward relay coil MF-C has normally closed contacts MF120-1 in the circuit for the reversing relay coil MR121C. These contacts will be closed if the eccentric pin does not engage since the relay coil CR1l3-C, which is energized when the inner eccentric is off a home position, has normally closed contacts CR1 13-3 in the initial circuit for energizing the motor forward coil 120C to assure that this circuit is broken when the eccentric pin properly engages. If it does not engage, the motor 62- will operate forwardly until the off-home position switch is actuated to open contacts CRl13-3 to stop the motor running in a forward direction, the holding circuit through contacts CR1112 or CRll1-3 not being effective since there was no engagement of the solenoid pin to pick up coil'CRlll-C.

When the outer eccentric has moved in a return direction sufficiently to open the off-home switch 128 to deenergize the relay coil CR1 13-C, the contacts CR1134 in the circuit for the motor reversing coil MR12l-C will be opened to stop movement of the motor in a reverse direction and the contact CRl13-3 will be closed to again initiate movement in a throw-off direction.

When the printing cylinder has been thrown to its OFF-PLATE position, the relay coil CR114-C will be energized by the closing of switch 130 and when the printing cylinder is in its ON-PLATE position, the relay coil CR1 l5-C is energized by the switch 132. The relay coils CRl14-C, CR1 l5-C have parallel connected, normally open contacts CR1l4C-l and CR1 l5C-1 in the circuit for controlling the auxiliary motor 102 and clutch 104. In theOFF-PLATE and ON-PLATE position, CRllG-C will be energized through the switch 120. In addition, the relay coil CR1 12-C will be energized because of the disengagement of the timing pin. These relays have contacts in the circuits for energizing the auxiliary motor for operating the unit so that the motor cannot be energized if one of these coils is not energized. The circuitry for controlling the motor 102 and the clutch 104 includes a clutch and motor forward relay coil MF122 and a motor reverse relay coil MRl23. The closing of the contacts of the relay coil CR1l0-C, CRlll-C, CRll2 C, CR1l3-C and of the contacts CR1 14-1 or of the contacts CR1 15-1 enable the circuit for energizing the motor forward or motor reverse relay coils MF122 and MR123 by inch push button 124 or'run push button 125 or reverse button 126. The depression of the inch push button 124 will complete a circuit to energize the motor forward coil MF122 for inching the auxiliary motor to drive the printing unit in a forward direction. If it is desired to operate the auxiliary motor in ajog manner in a reverse direction, the reverse push button 126 is depressed.

if it is desired to run the auxiliary unit continuously in a forward direction during make ready or clean up, the inch and run push buttons 124, 125 may be both pushed to energize the motor forward relay coil 122 and to complete a circuit to a holding coil CR1l7-C which has holding contacts CRl17-l and CR117-2 connected across the inch switch 124 and the rim switch 125, respectively.

When the blanket and impression cylinder gears are to be reconnected, the switch 120 is set to the connect position. In this position, only the contacts 1208 of the switch are closed and the relay coil CR1l6-C is deenergized to close its contacts-in a circuit'for energizing a time delay relay coil TRl27-C to effectdeenergization of the timing pin solenoid by opening contacts TRl27-l. When the printing cylinder is in its ON- PLATE or OFF-PLATE position, the timing pin solenoid is maintained energized through a holding circuit which includes normally open contacts CR1 12-3 of the relay coil CRll2 which is energized as long as the timing pin is disengaged and the normally closed contacts TRl27-l of a time delay relay coil TRl27-C so that the timing pin cannot be reinserted until the relay TR127-C is energized. The circuit for energizing the relay TRl27-C includes contacts l28CR1-A which are controlled by a relay on the main press panel which must be set'to a connect position before the relay TRl27-C can be energized. This is to assure that all units are ready to be connected before reconnection can be effected. However, eachunit may be provided with an idle switch which would enable the press to run with the unit in a disconnect condition. The circuit for energizing relay coil TRl27-C also includes the normally open contacts CRlll-4 of the relay coil CRlll-C which is energized when the eccentric pin is engaged and the contacts CR1 13-4 of the relay CR1 13-C which is energized when the eccentric has moved off of its normal position to an OFF-PLATE or ON-PLATE position. Consequently, when the contacts l28CR1-A are closed, the relay TRl27-C is energized and the timing pin solenoid is de-energized to allow the timing gears to be reconnected. The relay coil in the main panel for operating the contacts l28CRl-A has normally open contacts of the relay coils CRll6-C of all units in series therewith so that the relay cannot be operated until all relay coils CR1 16-C are de-energized by operation of the disconnect switch 120 to a connect position. When all the press units have their switches 120 in the connect position or overridden ,by the unit idle switch, the relay coil for operating the contacts '128CR1-A in all the units may be energized to energize the relay coils TRl27-C in all of the units to reconnect the timing pins. When this happens, the holding circuit through the contacts CR127-l for the timing pin solenoid is broken and the timing pin solenoid in each unit is de-energized to move inwardly and ride on its cooperating timing gear, which is rotated by driving the main drive and the impression cylinders of the press, until the pin is received in the opening to interconnect the timing gears to cause rotation of the printing cylinder and the plate cylinders with the impression cylinder.

When the timing pin is engaged, the. relay coil CR1 l2-C is de-energized. When this relay coil is deenergized, its contacts CRl12-4 are closed to operate the eccentric adjustment motor 62 in a reverse direction by energizing the motor control coil MRl2l-C.

The motor will move the outer eccentric until it returns the inner eccentric to a home position atwhich time the relay coil CR1 13C is de-energized to cause the eccentric pin solenoid to be de-energized to withdraw the eccentric pin. At this point, the stock-thickness adjustment is to be reestablished and the blanket cylinder can be thrown on pressure by operating the conventional throw mechanism.

The control for the main drive motor has contacts operated by the relay coil CRl13-C in series with the run switch of the main motor drive so that it cannot be operated at a run speed unless the inner eccentric is in a home position.

' In FIG. '9, the relay' CR1 l6-C is shown as having contacts CR1 16-6 in a circuit between junctions M and N. The junctions M and N are connected in series with the relay on the main control panel for operating the connect contacts 28CRl-A. Since each unit has such 7 contacts, the relay 128CR1-A cannot be operated to start-the reconnect sequence, until all units have been set to a connect condition. A unit idle switch OR at each unit may be operated to close contacts in parallel with the contacts CR1166 to allow the unit to be idle. Also, the relay CR1l6-C has contacts CR1l6-5 connected in parallel with contacts CR1 10-3 of relay coil CR1l0-C between junctions R and S. These contacts are in series with contacts of coil CR1 13-C which is energized when the inner eccentric is off its home position. The junctions R-S are connected in series with the run speed control circuit for the main drive motor so that this circuit is not operative when the contacts CR1 13-4 are open or both of the contacts CR1 16-5 and CR1 10-3 are open. The contacts CR1 10-3 and the contacts CRl16-5 are open if the connect switch for the unit is placed in an OFF-PLATE or an ON-PLATE l3 condition and the blanket cylinder is off pressure. The contacts CR113-4 are open whenever the inner eccentric is off of its home position. Consequently, the main drive motor cannot be operated at run speed until all the selector switches have been set to their connect position and the inner eccentric has been returned to its home position.

It will be appreciated from the foregoing that the existing stock thickness adjustment mechanism, including the outer eccentrics, are part of the means employed for disconnecting the blanket cylinder from the main press drive. To assure that upon reconnection of the blanket cylinder, the previously established stock thickness setting is maintained, an additional mechanism, illustrated in FIG. 7, is preferably provided. As shown in that Figure, the stock thicknessadjustment mechanism includes a bracket'150 received over the shaft 151 for the gear 57. The bracket 150 supports a solenoid 152 and a pivotally supported arm 154. The arm 154 includes a nose portion 156 which is engageable with a notch 158 in a disk 159 rotatable with the gear 57. A guide bracket 160 is supported on the press frame and includes an arcuate slot 162, the arcuate extent of which corresponds to the arc through which the gear 57 is normally rotated to adjust the stock thickness. The pivotal support 164 for the arm 154 extends through slot 162 and includes a latch member in the form of a rotatable eccentric I66.

In the'operation of the stock thickness setting indicator mechanism illustrated in FIG. 7, the solenoid 152 is normally deenergized and the arm 154 is'thereby spring biased to a position in which the nose 156 is engaged in the notch 158 thereby connecting the bracket 150 to the gear 57. Upon rotation of the shaft 151, the disk 159, the bracket 150, the arm 154 and the solenoid 152 rotate with the shaft, the slot 162 in the bracket 160 accommodating the angular movement of the bracket 150 and its associated mechanism. It will be apparent that for each angular position of the disk 159, the pivotal support 164 for the arm 154 will assume a corresponding position along the slot 162. When it is desired to use the stock thickness mechanism to disengage the blanket cylinder from the impression cylinder, the solenoid 152 is energized by the energization of the relay coil CR1l6-C thereby withdrawing the nose 156 of the arm 154from the notch 158 in the disk 159. This disconnects the bracket 150 from the gear 57 and permits the disk 159 to rotate independently of the bracket. However, the bracket 150 remains in its angularly adjusted position along slot 162 by virtue of an eccentric 166. More specifically, as the arm 154 is pivoted to withdraw the nose 166 from the notch 158 the eccentric 166 is rotated and, in effect, wedges in the slot 162 to latch the bracket 150 to the bracket 160. As a result, the bracket 150 remains in the position at which the disk 159 was last set and thus maintains the stock thickness setting of the disk 159 while the stock thickness mechanism is being used for the disengaging operation. When the selector switch is moved to its connect position, the deenergization of relay CR1 16-C deenergizes solenoid 152 and the spring bias on its armature urges the nose of arm 154 against the disk 159. The arm 154 cannot move inwardly to release the eccentric lock because it engages and rides on the periphery of the disk 159.

When the inner eccentric returns to its home position during reconnection, the stock thickness adjustment has yet to be made. As an example, the eccentric pin may be engageable when the blanket and impression cylinders are separated by 0.035 inches which is approximately the home position. The conventional off pressure position for maximum stock thickness may be 0.030 inches so that the inner eccentric must move at least 0.005 inches on return to reach the off pressure position for maximum stock thickness. Accordingly, the motor 62 is not stopped when the eccentric is to be automatically returned to its stock thickness adjustment. In this case, the motor continues to operate until the nose 156 enters notch 158 and engages an insulated contact 170 in the bottom of the notch to energize the unlatch coil 174U of a latching relay 174R which has contacts l74R-l in parallel with the contacts 'CRl13-4 in the circuit 'for energizing the motor 62. The latching relay is latched in to close its contacts 174R-1 and contacts 174R-2 by the energization of relay coil CR1 12-C on the disengagement of the timing pm.

From the foregoing, it can beseen that the present invention has provided a new and improved printing press in which the printing cylinder, the blanket cylinder in a lithographic sheet-fed printing press, can be disconnected from the main press drive and the printing cylinder together with theplate cylinder if the press has both a blanket and a plate cylinder, may be driven independently from the main drive for make-ready purposes. Even though the printing units are disconnected, the main drive is maintained intact so that sheets may be fed through the printing press, if desired. Moreover, the main drive is operated to rotate the impression cylinders when the blanket cylinders are to be reconnected and timing means will operate automatically to reconnect the printing cylinder to the main drive when the printing cylinder and the impression cylinder are in their proper relationship. While all of the units preferably include a disconnect for disconnecting the printing cylinder from the main drive, it will be understood that the main drive could be used to drive one of the units, particularly in a two-unit press, and blanket cylinder disconnects and auxiliary drives provided for the other 1 units. However, in such an arrangement, sheets could not be carried to a printing press at the option of those operating on the disconnected units during the makeready operation. j

In addition, the present invention has provided a novel structure and manner for disconnecting the image carrying cylinders of a printing press to disconnect them from the main press drive and to effect a reconnect to the drive.

We claim:

1. In a multi-unit printing press having a plurality of units comprising a printing cylinder and a second cylinder cooperating with said printing cylinder to form a printing nip in each of said units, a drive train interconnecting said cylinders, said drive train including means for operating said drive train to drive said press during v printing, means supporting each of said printing cylinders for movement between a printing position and a nonprinting position, said drive train including a respective cylinder gear operatively associated with each printing cylinder for movement with the cylinder and a cooperating drive gear, said cylinder gears and drive gears remaining in mesh when said printing cylinders are moved to said nonprinting position, said means for supporting at least one of said printing cylinders including, means which is operable to move the printing cylinder to a further position in which the corresponding cylinder gear and drive gear are out of mesh to disconnect the cylinder gear and the printing cylinder from said drive train, means for actuating said means for supporting at least one of said printing cylinders to move said one printing cylinder to a selected one of its positions, means for driving said one of said printing cylinders independently of said drive train when said drive and cylinder gears are out of mesh, each of said units having a printing cylinder gear which moves out of engagement with its drive gear to said further position including timing means for effecting re-engagement of the cylinder and drive gears in the proper angular relationship.

2. In a printing press as defined in claim 1 wherein said means for effecting re-engagement of the cylinder and drive gears includes means for automatically interconnecting the drive and cylinder gears of the unit when the latter have a particular angular relationship, and said means for driving said one of said printing cylinders is operable to drive said drive gears when a cooperating cylinder gear is out of engagement therewith to position said means for effecting re-engagement of the cylinder and drive gears preparatory to re-engaging said'cylinder and drive gears.

3. A printing press as defined in claim 1 wherein said means for supporting each printing cylinder comprises an eccentric which is rotatable to move the printing cylinder of the unit between printing and nonprinting conditions and for adjusting the printing position of the printing cylinder while the cylinder gear and the correspondingdrive gear are in mesh and said actuating means rotates said eccentric to move said printing cylinder away from its printing position to effect a disengagement' of the corresponding cylinder and drive gears. g

4. A printing press as defined-in claim lwherein each of said means for supporting each printing cylinder comprises a first eccentric operable to move the printing cylinder between printing and nonprinting positions, :1 second eccentric to adjust the printing position of the printing cylinder, and said actuating means comprises means connected to rotate said second eccentric.

5. A printing press as defined in claim 4 wherein said printing cylinders are blanket cylinders and said printing press includes a'plate cylinder in each unit for cooperating with the blanket cylinder and said, actuating means is operable to selectively move the blanket cylinder to a position clear of the cooperating plate cylinder or to a position in engagement with the plate cylinder with the cylinder gear and drive gear out of engagement.

6. In a multi-unit printing press as defined in claim 1 wherein each of said units includes a plate cylinder and said printing cylinder is a blanket cylinder and the means for supporting each printing cylinder which is movable to disengage its cylinder gear from the cooperating drive gear is operable 'to selectively move the blanket cylinder to a plurality of positions where the cylinder gear is out of mesh with its drive gear including a first position in which the blanket cylinder is clear of a plate on the plate cylinder and a second position in which it runs in engagement with a plate on the plate cylinder.

7. In a printing press as defined in claim 1 wherein each drive gear is operable to drive the second cylinder and said cylinder gear of the corresponding unit, and said means for supporting each unit which has a cylinder gear movable out of mesh with a drive gear comprising means for moving said printing cylinder between printing and non-printing positions where the drive and cylinder gears are in mesh and to a third nonprinting position where the drive and cylinder gears are out of mesh.

8. A printing press as defined in claim 1 in which said printing units are units for printing sheets and each said second cylinder comprises an impression cylinder for carrying sheets into a nip formed by the printing cylinder and the second cylinder, said printing press comprising transfer cylinder means for transferring sheets between printing units and said drive train comprises a gear train interconnecting said transfer cylinder means and said drive gears, said drive gears being mounted on said impression cylinders.

9. A printing press as defined in claim 8 wherein said means for operating feed drive train is operable to drive said transfer cylinder means and said impression cylinders to carry sheets through the press with a cylinder gear for a printing cylinder out of mesh with its drive gear. I

10. A printing press as defined .in claim 9 wherein said press includes control means for preventing operation of said means for operating the drive train at normal printing speeds when a drive gear and its corresponding said cylinder gear are disengaged.

11. A printing press for printing on sheet material, said printing press comprising a plurality of printing units, each of said printing units includingva printing cylinder and a second cylinder. cooperating to define a printing nip, main drive means for driving said cylinders in said plurality of printing units during operation of said printing press and for maintaining a predetermined rotational relationship between said cylinders in said plurality of printing units during operation of said printing press, said main drive means including a first gear which is connected-with a printing cylinder in one of said printing units and a second gear which is connected with said second cylinder in said one printing unit, means-insaid one printing unit for supporting said printing cylinder in said one printing unit for movement between a printing position in which said first gear is in meshing engagement with said second gear to maintain said printing cylinder in said one printing unit in said predetermined rotationalrelationship with said printing cylinders in said other printing units and a nonprinting position in which said first gear is out of mesh with said second gear, said printing cylinder in said one printing unit being rotatable relative to the printing cylinders in said other printing units to thereby move said printing cylinder in said one printing unit out of the predetermined rotational relationship with the printing cylinders in the other printing units when said printing cylinder in said one printing unit is in said nonprinting position, means in said one printing unit for moving said printing cylinder in said one printing unit between said printing and nonprinting positions, means for driving said printing cylinder in said one printing unit when said printing cylinder in said one unit is in said nonprinting position, and means for preventing movement of said printing cylinder in said one printing unit from said nonprinting position to said printing position when said printing cylinder in said one printing unit is out of said predetermined rotational relationship with said printin'g 'cylinders in said other printing units.

12 A multi-unitprinting press as set forth in claim 1 1 wherein saidmeans for moving saidprinting cylinder between said printing and nonprinting positions includesstock thickness adjustment means for setting the spacing between said printing and second cylinders in said one'unit to any one of a plurality of distances to accommodate any one of a plurality of thicknesses of sheet material, said stock thickness adjustment means being operated from an initial setting to a second setting up'on movement of said printing cylinder in said one unit from said printing position to said nonprinting position, and means for returning said stock thickness adjustment means to said initial setting upon movement of said printing cylinder in said one printing unit from saidnonprinting position to said printing position.

13. A multi-unit printing press as set forth in claim 12 wherein said stock thickness adjustment means includes driving and driven members, and drive means for moving said driving and driven members'relative to each other to adjust the setting of said stock thickness adjustment means to the initial setting when said printing cylinder in said one unit is in said printing position and for moving said driving and driven members relative to each other to effect operation of said stock I thickness adjustment means to the second setting upon movement of said printing cylinder in said one unit to said nonprinting position.

14. A multi-unit printing press as set forth in claim 12 wherein said means for moving said printing cylinder between said printing and nonprinting positions further includes throw-off means for moving said printing cylinder in said one printing unit between said printing position and a thrown-off position intermediate said printing and non-printing positions, said first and second gears being disposed in meshing engagement when said printing cylinder in said one printing unit is in said thrown-off position, said stock thickness adjustment means being maintained at said initial setting during movement of said printing cylinder in said one unit between said printing and thrown-off positions.

15. A multi-unit printing press as set forth in claim 14 wherein said throw-off means includes a first eccentric operatively connected with said printing cylinder in said one unit and means for rotating said first eccentric to effect movement of said printing cylinder in said one unit between said printing and thrown-off positions, said stock thickness adjustment means including a second eccentric operatively connected with said printing cylinder in said one unit and means for rotating said second eccentric to change the setting of said stock thickness adjustment means and effect movement of said printing cylinder in said one unit independently of said first eccentric to vary the spacing between said printing and second cylinders in said one unit.

16. A multi-unit printing press as set forth in claim 15 wherein said means for moving said printing cylinder between said printing and nonprinting positions further includes coupling means for interconnecting said first and second eccentrics to effect movement of said printing cylinder in said one printing unit between the printing and nonprinting positions under the combined influence of said first and second eccentrics.

17. A multi-unit printing press as set forth in claim 16 wherein said coupling means is operable between an engaged condition interconnecting said first and second eccentrics and a disengaged condition in which said, first and second eccentrics are rotatable independently of each other.

18. A multi-unit printing press as set forth in claim 11 wherein said means for driving said printing cylinder in said one unit when said printing cylinder in said one unit is in said nonprinting position includes secondary drive means for driving said printing cylinder in said one printing unit independently of said main drive means.

19. A printing press for printing on sheet material, said printing press comprising a rotatable printing cylinder, a rotatable second cylinder operatively connected with said printing cylinder, said printing cylinder being movable relative to said second cylinder between a printing position, a thrown-off position and a nonprinting position, said printing and second cylinders having their axes of rotation spaced a first distance apart and cooperating to define a printing nip when said printing cylinder is in said printing position, said printing and second cylinders having their axes of rotation spaced apart by a second distance which is greater than said first distance when said printing cylinder is in' said thrown-ofi position, said printing and second cylinders having their axes of rotation spaced apart by a third distance which is greater than said second distance when said printing cylinder is in said nonprinting position, main drive means for rotating said printing and second cylinders when they'are in the printing position, throw-off means for moving said printing cylinder between said printing and thrown-off position, stock thickness adjustment means operable toany one of a plurality of settings to vary said first distance and the spacing between said printing and second cylinders to accommodate anyone of a plurality of thicknesses of sheet material when said printing cylinder is in said printing position, said throw-off means being effective to move said printing cylinder between said printing and thrown-off positions without changing the setting of said stock thickness adjustment means from an ini tial setting corresponding to a particular thickness of sheet material, means for effecting operation of said stock thickness adjustment means from said initial setting to a second setting to effect movement of said printing cylinder to said nonprinting position, and means for returning said stock thickness adjustment means to said initial setting upon movement of said printing cylinder from said nonprinting position to said printing position.

20. A printing press as set forth in claim 19 wherein said throw-off means includes a first eccentric operatively connected with said printing cylinder and means for rotating said first eccentric to effect movement of said printing cylinder between said printing and thrown-off positions, said stock thickness adjustment means including a second eccentric operatively con nected with said printing cylinder and means for rotating said second eccentric to effect movement of said printing cylinder to vary the setting of said stock thickness adjustment means.

21. A printing press as set forth in claim 20 further includes coupling means for interconnecting said first and second eccentrics.

22. A printing press as set forth in claim 19 further including main drive means for rotating said printing and second cylinders when said printing cylinder is in 19 said printing position and when said printing cylinder is in said thrown-off position, said drive means including a first gear connected with said printing cylinder and a second gear connected with said second cylinder, said first and second gears being disposed in meshing engagement when said printing and second cylinders are in said printing and thrown-off positions, said first and second gears being out of meshing engagement when said printing and second cylinders are in said nonprinting positions.

23. A printing press as set forth in claim 19 wherein of said drive means. 

1. In a multi-unit printing press having a plurality of units comprising a printing cylinder and a second cylinder cooperating with said printing cylinder to form a printing nip in each of said units, a drive train interconnecting said cylinders, said drive train including means for operating said drive train to drive said press during printing, means supporting each of said printing cylinders for movement between a printing position and a nonprinting position, said drive train including a respective cylinder gear operatively associated with each printing cylinder for movement with the cylinder and a cooperating drive gear, said cylinder gears and drive gears remaining in mesh when said printing cylinders are moved to said nonprinting position, said means for supporting at least one of said printing cylinders including, means which is operable to move the printing cylinder to a further position in which the corresponding cylinder gear and drive gear are out of mesh to disconnect the cylinder gear and the printing cylinder from said drive train, means for actuating said means for supporting at least one of said printing cylinders to move said one printing cylinder to a selected one of its positions, means for driving said one of said printing cylinders independently of said drive train when said drive and cylinder gears are out of mesh, each of said units having a printing cylinder gear which moves out of engagement with its drive gear to said further position including timing means for effecting re-engagement of the cylinder and drive gears in the proper angular relationship.
 2. In a printing press as defined in claim 1 wherein said means for effecting re-engagement of the cylinder and drive gears includes means for automatically interconnecting the drive and cylinder gears of the unit when the latter have a particular angular relationship, and said means for driving said one of said printing cylinders is operable to drive said drive gears when a cooperating cylinder gear is out of engagement therewith to position said means for effecting re-engagement of the cylinder and drive gears preparatory to re-engaging said cylinder and drive gears.
 3. A printing press as defined in claim 1 wherein said means for supporting each printing cylinder comprises an eccentric which is rotatable to move the printing cylinder of the unit between printing and nonprinting conditions and for adjusting the printing position of the printing cylinder while the cylinder gear and the corresponding drive gear are in mesh and said actuating means rotates said eccentric to move said printing cylinder away from its printing position to effect a disengagement of the corresponding cylinder and drive gears.
 4. A printing press as defined in claim 1 wherein each of said means for supporting each printing cylinder comprises a first eccentric operable to move the printing cylinder between printing and nonprinting positions, a second eccentric to adjust the printing position of the printing cylinder, and said actuating means comprises means connected to rotate said second eccentric.
 5. A printing press as defined in claim 4 wherein said printing cylinders are blanket cylinders and said printing press includes a plate cylinder in each unit for cooperating with the blanket cylinder and said actuating means is operable to selectively move the blanket cylinder to a position clear of the cooperating plate cylinder or to a position in engagement with the plate cylinder with the cylinder gear and drive gear out of engagement.
 6. In a multi-unit printing press as defined in claim 1 wherein each of said units includes a plate cylinder and said printing cylinder is a blanket cylinder and the means for supporting each printing cylinder which is movable to disengage its cylinder gear from the cooperating drive gear is operable to selectively move the blanket cylinder to a plurality of positions where the cylinder gear is out of mesh with its drive gear including a first position in which the blanket cylinder is clear of a plate on the plate cylinder and a second position in which it runs in engagement with a plate on the plate cylinder.
 7. In a printing press as defined in claim 1 wherein each drive gear is operable to drive the second cylinder and said cylinder gear of the corresponding unit, and said means for supporting each unit which has a cylinder gear movable out of mesh with a drive gear comprising means for moving said printing cylinder between printing and non-printing positions where the drive and cylinder gears are in mesh and to a third non-printing position where the drive and cylinder gears are out of mesh.
 8. A printing press as defined in claim 1 in which said printing units are units for printing sheets and each said second cylinder comprises an impression cylinder for carrying sheets into a nip formed by the printing cylinder and the second cylinder, said printing press comprising transfer cylinder means for transferring sheets between printing units and said drive train comprises a gear train interconnecting said transfer cylinder means and said drive gears, said drive gears being mounted on said impression cylinders.
 9. A printing press as defined in claim 8 wherein said means for operating feed drive train is operable to drive said transfer cylinder means and said impression cylinders to carry sheets through the press with a cylinder gear for a printing cylinder out of mesh with its drive gear.
 10. A printing press as defined in claim 9 wherein said press includes control means for preventing operation of said means for operating the drive train at normal printing speeds when a drive gear and its corresponding said cylinder gear are disengaged.
 11. A printing press for printing on sheet material, said printing press comprising a plurality of printing units, each of said printing units including a printing cylinder and a second cylinder cooperating to define a printing nip, main drive means for driving said cylinders in said pluRality of printing units during operation of said printing press and for maintaining a predetermined rotational relationship between said cylinders in said plurality of printing units during operation of said printing press, said main drive means including a first gear which is connected with a printing cylinder in one of said printing units and a second gear which is connected with said second cylinder in said one printing unit, means in said one printing unit for supporting said printing cylinder in said one printing unit for movement between a printing position in which said first gear is in meshing engagement with said second gear to maintain said printing cylinder in said one printing unit in said predetermined rotational relationship with said printing cylinders in said other printing units and a nonprinting position in which said first gear is out of mesh with said second gear, said printing cylinder in said one printing unit being rotatable relative to the printing cylinders in said other printing units to thereby move said printing cylinder in said one printing unit out of the predetermined rotational relationship with the printing cylinders in the other printing units when said printing cylinder in said one printing unit is in said nonprinting position, means in said one printing unit for moving said printing cylinder in said one printing unit between said printing and nonprinting positions, means for driving said printing cylinder in said one printing unit when said printing cylinder in said one unit is in said nonprinting position, and means for preventing movement of said printing cylinder in said one printing unit from said nonprinting position to said printing position when said printing cylinder in said one printing unit is out of said predetermined rotational relationship with said printing cylinders in said other printing units.
 12. A multi-unit printing press as set forth in claim 11 wherein said means for moving said printing cylinder between said printing and nonprinting positions includes stock thickness adjustment means for setting the spacing between said printing and second cylinders in said one unit to any one of a plurality of distances to accommodate any one of a plurality of thicknesses of sheet material, said stock thickness adjustment means being operated from an initial setting to a second setting upon movement of said printing cylinder in said one unit from said printing position to said nonprinting position, and means for returning said stock thickness adjustment means to said initial setting upon movement of said printing cylinder in said one printing unit from said nonprinting position to said printing position.
 13. A multi-unit printing press as set forth in claim 12 wherein said stock thickness adjustment means includes driving and driven members, and drive means for moving said driving and driven members relative to each other to adjust the setting of said stock thickness adjustment means to the initial setting when said printing cylinder in said one unit is in said printing position and for moving said driving and driven members relative to each other to effect operation of said stock thickness adjustment means to the second setting upon movement of said printing cylinder in said one unit to said nonprinting position.
 14. A multi-unit printing press as set forth in claim 12 wherein said means for moving said printing cylinder between said printing and nonprinting positions further includes throw-off means for moving said printing cylinder in said one printing unit between said printing position and a thrown-off position intermediate said printing and non-printing positions, said first and second gears being disposed in meshing engagement when said printing cylinder in said one printing unit is in said thrown-off position, said stock thickness adjustment means being maintained at said initial setting during movement of said printing cylinder in said one unit between said printing and thrown-off positions.
 15. A multi-unit prInting press as set forth in claim 14 wherein said throw-off means includes a first eccentric operatively connected with said printing cylinder in said one unit and means for rotating said first eccentric to effect movement of said printing cylinder in said one unit between said printing and thrown-off positions, said stock thickness adjustment means including a second eccentric operatively connected with said printing cylinder in said one unit and means for rotating said second eccentric to change the setting of said stock thickness adjustment means and effect movement of said printing cylinder in said one unit independently of said first eccentric to vary the spacing between said printing and second cylinders in said one unit.
 16. A multi-unit printing press as set forth in claim 15 wherein said means for moving said printing cylinder between said printing and nonprinting positions further includes coupling means for interconnecting said first and second eccentrics to effect movement of said printing cylinder in said one printing unit between the printing and nonprinting positions under the combined influence of said first and second eccentrics.
 17. A multi-unit printing press as set forth in claim 16 wherein said coupling means is operable between an engaged condition interconnecting said first and second eccentrics and a disengaged condition in which said first and second eccentrics are rotatable independently of each other.
 18. A multi-unit printing press as set forth in claim 11 wherein said means for driving said printing cylinder in said one unit when said printing cylinder in said one unit is in said nonprinting position includes secondary drive means for driving said printing cylinder in said one printing unit independently of said main drive means.
 19. A printing press for printing on sheet material, said printing press comprising a rotatable printing cylinder, a rotatable second cylinder operatively connected with said printing cylinder, said printing cylinder being movable relative to said second cylinder between a printing position, a thrown-off position and a nonprinting position, said printing and second cylinders having their axes of rotation spaced a first distance apart and cooperating to define a printing nip when said printing cylinder is in said printing position, said printing and second cylinders having their axes of rotation spaced apart by a second distance which is greater than said first distance when said printing cylinder is in said thrown-off position, said printing and second cylinders having their axes of rotation spaced apart by a third distance which is greater than said second distance when said printing cylinder is in said nonprinting position, main drive means for rotating said printing and second cylinders when they are in the printing position, throw-off means for moving said printing cylinder between said printing and thrown-off position, stock thickness adjustment means operable to any one of a plurality of settings to vary said first distance and the spacing between said printing and second cylinders to accommodate any one of a plurality of thicknesses of sheet material when said printing cylinder is in said printing position, said throw-off means being effective to move said printing cylinder between said printing and thrown-off positions without changing the setting of said stock thickness adjustment means from an initial setting corresponding to a particular thickness of sheet material, means for effecting operation of said stock thickness adjustment means from said initial setting to a second setting to effect movement of said printing cylinder to said nonprinting position, and means for returning said stock thickness adjustment means to said initial setting upon movement of said printing cylinder from said nonprinting position to said printing position.
 20. A printing press as set forth in claim 19 wherein said throw-off means includes a first eccentric operatively connected with said printing cylinder and means for rotating said first eccentric to effect movement of said printing cylinder between said printing and thrown-off positions, said stock thickness adjustment means including a second eccentric operatively connected with said printing cylinder and means for rotating said second eccentric to effect movement of said printing cylinder to vary the setting of said stock thickness adjustment means.
 21. A printing press as set forth in claim 20 further includes coupling means for interconnecting said first and second eccentrics.
 22. A printing press as set forth in claim 19 further including main drive means for rotating said printing and second cylinders when said printing cylinder is in said printing position and when said printing cylinder is in said thrown-off position, said drive means including a first gear connected with said printing cylinder and a second gear connected with said second cylinder, said first and second gears being disposed in meshing engagement when said printing and second cylinders are in said printing and thrown-off positions, said first and second gears being out of meshing engagement when said printing and second cylinders are in said nonprinting positions.
 23. A printing press as set forth in claim 19 wherein said stock thickness adjustment means includes an eccentric which is rotatable relative to said printing cylinder and drive means for rotating said eccentric to vary the setting of said stock thickness adjustment means when said printing cylinder is in the printing position, said means for effecting operation of said stock thickness adjustment means from said initial setting to said second setting including means for effecting operation of said drive means. 